In conventional memory programming, such as NAND or other flash programming trim setting methods, program trim information is stored in a peripheral area. Further, only one trim set is used and applied to on die, that is to all blocks and all word lines of the NAND device. However, in the case of pitch doubling pattering technology, which is becoming common in NAND devices, the critical dimension differences between even and odd column and row lines is increasing. This is due to decreased uniformity of side wall oxides and etching. A single trim setting is not suitable for all pages for effective trim setting.
For example, certain combinations of active area of the lines on which signals are passing and the gate size of transistors involved in programming or read operations will program or read much more quickly than others. A trim setting suitable for a fast read or program is not necessarily suitable for a slow read or program operation.
For the reasons stated above, and for other reasons stated below which will become apparent to those skilled in the art upon reading and understanding the present specification, there is a need in the art for an improved trim setting method and memory.